Artificial rice can be produced using a variety of methods from a variety of starch sources. An artificial rice allows the introduction of additional nutrients and flavorings into the granule that are not present naturally.
U.S. Pat. Nos. 3,620,762 and 3,628,966 provide a method for producing an enriched rice product. The method includes forming an enriched rice starch, heating the mixture so that it is partially gelatinized (semigelatinized) and taking this viscous product and forming it into granules resembling rice granules and coating each granule with a waterproof coating. This method is cumbersome, and the requirements of the semigelatinizing step and coating step increase the cost of production.
Japanese patent HEI 4-13986, assigned to the assignee of the present invention, discloses a method of forming shaped granules of starch from non-rice sources. The starch is isolated, mixed with water and kneaded and then formed into artificial rice granules using a rolling granulator. The artificial rice granules do not require a coating nor is a semigelatinizing step required. The artificial rice that is formed retains a rice-like texture and consistency upon cooking.
Japanese patent HEI 3-69267, also assigned to the assignee of the present invention, discloses a method of forming a decorated artificial rice in which color is introduced by combining the starch with extracts from vegetables, fruits, herbs, mushrooms, seafood and seaweed. The patent further discloses that these additives may make an enriched artificial rice by adding nutrients.
Both the HEI 4-13986 and HEI 3-69267 patents prepare the artificial rice so that it can be cooked using the Japanese cooking method of boiling in only 1.5 times the volume of water as rice. However, in the United States, the Indica strain of rice is preferred. The cooking method for the Indica strain of rice requires that the cooking water be at least twice the volume of the rice, which can be referred to as the American method. Therefore, any artificial rice introduced into the United States should conform to the cooking method that is most common in order to have consumer acceptance.
An artificial rice which contains 2% or more of vegetable matter and made by the above methods cannot be properly prepared using water at twice the volume of rice. The rice granules turn to a sticky gel and loose their rice-like texture or shape when cooked with the American method.
U.S. Pat. No. 4,129,900 discloses a method of preparing shaped granules of starch which includes water-soluble gelling hydrocolloids. The use disclosed for such granules is in puddings which are retorted or aseptically packaged. The method allows the formation of translucent pearls of gelatinized starch granules, i.e. tapioca-like, upon cooking. However, because of their formation and composition, the granules do not lend themselves to use in non-pudding applications. When cooked using the American method for rice preparation, the granules have a pasta-like texture. The high shear of the extrusion method used to form the granules destroys the starch micro-particles giving rise to a product with a gummy texture unlike that of native rice.
U.S. Pat. No. 5,211,977 discloses a method of preparing a starch-based mixture that includes a starch source, flavorings including vegetable powders, from 3% to 10% dried weight, an emulsifier and hydrocolloid which is used to form a pasta product. The pasta is formed using a pressure extrusion process. However, this starch-based 10 mixture cannot be used in a rolling granulator. If the granulator is maintained at an elevated temperature, i.e. above 60.degree. C., the starch-based mixture will adhere to the granulator. If the granulator is maintained at a cooler temperature, i.e. below 60.degree. C., the mixture is too hard to form granules.